1. Field of the Invention
This invention relates to pressure vessels for compressed gases at very high pressures of at least 200 kilograms per square centimeter.
2. Description of Prior Art
Hitherto, it has been usual for such pressure vessels (which are often known by the term of "bottles") to be mounted in a retaining structure and for them to be connected to a point of use by couplings which are separate from the mountings and which require the use of spanners or other tools for their attachment to the bottles. Examples of this kind of coupling are described in British Pat. No. 1,308,491 although the couplings therein are intended for pressures substantially lower than those contemplated for the present invention. While existing mounting and coupling systems are suitable for many purposes, the processes involved in changing an expended bottle for a full one--including release of the coupling from the expended bottle by the use of a spanner, release and removal of the expended bottle from the mounting, positioning and attaching of the new bottle in the mounting, and attachment of the coupling to the new bottle, again with the use of a spanner--take a considerable length of time during which the equipment using the gas will be deprived of such gas. While in some applications it may be possible to have a standby bottle already mounted and coupled, duplicate mountings and couplings are not always acceptable, for example for reasons of weight, space and cost. Also, the need to use a tool such as a spanner can be a disadvantage in adverse conditions, for example in cold climates where mitts must be worn, where dexterity may be reduced and spanners may be dropped or lost.